Dip-pen nanolithography (DPN) has been developed to dispense material by molecular transport from a cantilever tip mounted on the probe of an atomic force microscope (AFM) onto a substrate surface as described in Science 283, 661 (1999). DPN is disadvantageous in that repeated re-inking of the dispensing tip is required to replenish molecules when large surface areas are to be patterned or when complex patterns are required. DPN also suffers from low speed and throughput due to its serial nature and limited scan size.
Another technique for nanopatterning involves a micropipette disposed on the tip of an AFM probe as described in Appl/Phys. Lett. 65 (5), 648 (1994). The micropipette technique suffers from the disadvantage of irregular shape of the micropipette, low reproducibility, and low resolution. The micropipette is difficult to integrate in array format to carry out massive pattering operations on one or more substrates.
Still another technique referred to as millipede:parallel read/write is described in IEEE Trans. on Nanotech. 1 (1), 39 (2002) and involves a cantilevered AFM probe having a heated tip able to write on a thermoplastic substrate by embossing the tip into the thermoplastic material. The technique does not dispense any material, but is illustrative for a massively parallel writing method using AFM probe arrays.